例： Where did your brother study before he joined the army?

　　過(guò)去完成時(shí)可表示截止過(guò)去某一時(shí)間動(dòng)作的總或動(dòng)作的結(jié)束。

　　例：By the end of last month. We had reviewed four books

　　By eight o`clock, he had finished his homework.

　　與這個(gè)時(shí)態(tài)連用的時(shí)間狀語(yǔ)常有：

　　by 1985, by eight o`clock, by then, by the end of last month, by the time when, when, as soon as, before 等連詞引導(dǎo)的時(shí)間狀語(yǔ)從句，表示主句動(dòng)作結(jié)束的時(shí)間。

　　現(xiàn)在進(jìn)行時(shí)主要用于：

　　表示現(xiàn)在或現(xiàn)階段正在進(jìn)行的動(dòng)作。

　　例： Listen, someone is crying.

　　What are you doing these days?

　　代替一般現(xiàn)在時(shí)，表示經(jīng)常性動(dòng)作或狀態(tài)，而含有某種感情色彩。

　　例： How are you feeling today?

　　你今天感覺(jué)怎樣?(顯得親切)

　　He is doing well in his lessons.

　　他的功課很好。(贊揚(yáng))

　　You are always boasting.

　　你老愛(ài)吹牛。(厭煩)

　　動(dòng)詞 go, come, leave, arrive 等表將要發(fā)生的動(dòng)作時(shí)。

　　例：They are leaving for Shanghai.

　　與這種時(shí)態(tài)連用的時(shí)間狀語(yǔ)常有：

　　now, these days, recently, this week 等。